Estimation Of Key Node For Opportunistic Network Based On Mutual Influence

Opportunistic network is a self-organizing network that does not require a complete path between the source node and the destination node,and uses the encounter opportunity brought by node movement to achieve communication.The invalid of some nodes will cause the message delivery mechanism of the opportunistic network to fail and affect the message delivery efficiency and connectivity.Therefore,estimating the key nodes in the opportunistic network to take corresponding protection measures can optimize and maintain the network,which has a very positive meaning for the message transmission of the opportunistic network.This thesis analyzes the current research of key node estimation methods and analyzes the communication characteristics of opportunistic networks.Due to the sparse distribution and frequent connections of nodes,some commonly used key node estimation methods will lose accuracy when estimating key node in the opportunistic network.In order to accurately estimate the key node in the opportunistic network,the thesis considers the time-varying characteristics of the opportunistic network topology,and proposes a key node estimation indicator based on mutual influence between nodes.This indicator comprehensively considers the timing of the topological connection of the opportunistic network and the connection relationship between the nodes.To obtain a time-varying information of the opportunistic network,the summary graph is defined to model the opportunistic network,the shortest path is defined to reflects the influence of the message transmission path between nodes.This indicator starts from the two perspectives of the message transmission path and the local topology of the network,the inverse square law is used to obtain the mutual influence and total influence value of node.Finally,the D-S evidence theory is used to combine the mutual influence and connection time of node to construct the key node estimation model and draw key node.The thesis analyzes the conflict factors between TN and CT,and uses the Dempster-safer evidence theory(D-S Theory)to merge the two indicators to propose the DST indicator and verified the accuracy of key node.the experimental results shows that compared with the TD and IF indicators,the DST indicator has a good performance.